1. Related Application
This application claims the benefit of co-pending provisional application Serial No. 60/039,357 filed Mar. 19, 1997.
2. Field of the Invention
This invention relates to the field of exercise equipment, and particularly to a mechanism for providing exercise resistance at a rotary actuator in both directions of rotation.
3. Prior Art
Various physical exercises require that exercise resistance be applied in opposite directions from a neutral position. A particular type of exercise machine requiring such application of exercise resistance is the type commonly referred to as a "multi-hip" machine for performing hip abduction, hip adduction, hip flexion and hip extension exercises. Examples of this type of machine are shown in commonly owned U.S. Pat. Nos. 5,308,304; 5,354,252; and 5,468,202. In these machines, exercise resistance is provided by a selectable weight stack coupled through a cable and pulley system to a rotary cam. A cushioned pad is coupled to the cam for performing the various hip exercises. As the cam is rotated in either direction from a neutral position, a cable is wound on the cam surface to cause the selected portion of the weight stack to be lifted. In these and similar prior art exercise machines, there is a substantial range of motion of the cam about the neutral position in which the cable is not in contact with the cam surface. Thus, the profile of the cam surface has no effect on the amount of the exercise resistance within this range of motion. This "dead zone" on either side of the neutral position detracts from the effectiveness of the exercise.